WARNING! This description may contain spoilers in the screencaps taken from the film.
The following firearms were used in the film Twelve:
Smith & Wesson Model 65
Charlie (Jeremy Allen White) pulls a Smith & Wesson Model 65 with a 3 inch barrel and pearl grips in his attempt to mug Lionel (Curtis James "50 Cent" Jackson III). Lionel takes the weapon from him and uses it in the climax.
Smith and Wesson Model 65 - .357 Magnum.
Charlie pulls his Smith & Wesson Model 65 on Lionel.
In a flashback Charlie shows White Mike his Smith & Wesson Model 65.
White Mike notices that Lionel has Charlie's gun after he busts into the wrong room.
Lionel turns the tables on Charlie and shoots him with his Glock 17 with a stainless slide. Chris's psychotic brother Claude (Billy Magnussen) also has a Glock 17.
Glock 17 (3rd Generation) with stainless steel slide - 9x19mm
Lionel shoots Charlie with his Glock 17.
Lionel shoots Nana point blank when he witness the murder.
Claude loads his Glock 17 when he hears gunshots.
Claude shoots his Glock 17 as he goes down the stairs.
Claude reloads his Glock 17.